Pesticide Basics Uses, Exposures, Types and Acute Effects

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Pesticide BasicsUses, Exposures, Types and Acute
Effects
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Did you know?

• 5 million at risk population (U.S. EPA, 1992)
• 250-500 physician-diagnosed cases occur per
  100,000 agricultural workers (Blondell, 1997).
• Migrant and seasonal farmworkers are especially
  at high risk
• 84 of American households used pesticides, most
  commonly insecticides (Whitmore et al, 1992)
• Homeowners use 5-10 lbs/ acre/yr on their lawns
  and gardens, many x greater than farmers apply
  to corn and soybean fields (Robinson et al, 1994).

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Did you know?

• Non -agricultural pesticide exposure as
  disinfectants widespread (e.g., pine oil
  cleaners, bathroom cleaning products, and
  cleaning materials for swimming pools).
• Non-Ag Sector a concern pest control,
  nurseries, greenhouses, and landscaping.
• The medical profession uses disinfectants to
  sanitize and sterilize surfaces and instruments.
• Organophosphate and pyrethroid insecticides most
  implicated for poisonings.
• Water chlorination is one of the largest (by
  tonnage) uses of pesticides.

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Where Are Pesticides Used?

• Forests to control insects and under-story
  vegetation
• Landscapes, parks, and recreational areas to
  control weeds, insects, and disease pests
• Rights-of-way along railroads and under electric
  wires to control vegetation
• Houses, schools, and commercial and office
  buildings to control insects, rodents, and
  fungi
• Boat hulls to control fouling organisms

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Where Are Pesticides Used?

• Aquatic sites to control mosquitoes and weeds
• Wood products to control wood-destroying
  organisms
• Food preparation areas to control insects and
  rodents
• Human skin to kill or repel insects
• Household pets to control fleas and ticks
• Livestock to control insects and other pests.

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Non Occupational Pesticide Encounters

• Accidental or intentional ingestion
• Food and water residues
• Contaminated clothing
• Treated wood/structures
• Residues on animals/carpets
• Garden residues
• Termite control
• Hazardous waste sites/spills

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Agriculture Pesticide Applications
Boom sprayer
Aerial
Enclosed cab
Backpack wand
Air blast sprayer
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Agriculture Jobs
Orchard thinner
Mixer loader
Picker
Flagger
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Professions Exposed to Pesticides

• Aerial equipment maintenance
• Agronomists
• Building maintenance work
• Emergency responders
• Entomologists
• Firefighters
• Forestry workers
• Formulating end product
• Greenhouse- nursery workers
• Hazardous waste workers
• Landscapers
• Livestock dippers and veterinarians

• Marina workers
• Medical personnel
• Park workers
• Plant pathologists
• Research chemistry
• Sewer work
• Storage/warehouse work
• Structural application
• Transporting pesticides
• Treating contaminated workers
• Vector control workers
• Wood treatment workers
• Work on highway or railroad rights of way

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Key Household Safety Points
Partly Trained Gorillas Always Run Down Streets
Doing Cartwheels

1. Proximity
2. Take home
3. Garden
4. Animals
5. Recycle
6. Decant
7. Storage
8. Disposal
9. Child play/daycare

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ROUTES OF EXPOSURE
OPs are readily absorbed Across the SKIN with
skin contact In the lungs with INHALATION of
pesticide contaminated air/dust In the gut by
INGESTION of pesticide residue on food/dirt/dust
Source EPA Protect Yourself from
Pesticides-Guide of Agricultural Workers
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Risk Factors for Occupational Pesticide Exposures

• Concentration of commercial preparations gt than
  diluted final product greater risk
• AG workers highest exposure risk in mixing,
  loading, applying, and flagging.

Source H Murphy - Cambodia
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Occupational Risk Factors

• Pregnant Women 1st trimester
• Field workers entering sprayed field before
  re-entry interval REI
• Residuals on skin and clothes
• How to remove PPE
• How to clean PPE
• Showering after use

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Evidence? Agriculture Risk Factors

• Indonesia
• Cocktail mixture of multiple products
• Spray frequency
• Skin contact gt wet clothing
• Use of toxic products (1a/Ib, II)
• Washington state
• Protective Chemically resistant boots
• Protective Full face respirators
• Risk Mixing and loading pesticides
• Risk Cleaning equipment
• Protective Using a workplace locker for PPE

Source H Murphy - Indonesia
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Preventing Pesticide Illness
Non-chemical Alternatives
Primary
Engineering Controls
Secondary
Personal Protective Equipment PPE
Tertiary
Its the law
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Risk factors for pesticide exposures at home

• Migrant families gt risk
• Childrens vulnerability
• Location near fields
• Take home pathway
• Pesticide storage and use in homes
• Multiple chemical sensitivities (MCS)

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Migrant Families

• Living conditions quality and location
• Communication language and literacy
• Immigration status
• Access to health care
• Diet

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Unintentional (Accidental)

• GI absorption from accidental ingestion acute
  poisonings
• Respiratory and dermal absorption from
  surrounding environment
• Hand to mouth activity in children

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Occupational

• Dermal is most important
• Inhalation is a common pathway
• Ingestion less common but can occur if not use
  gloves or poor hygiene

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Intentional (Suicide/Homicide/Abuse)

• Ingestion is primary pathway
• Inhalation is another pathway, although primary
  agents of abuse in this manner are non-pesticide
  chemicals (aromatic solvents).

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Washington State Source of Case Reports 2002 and
2003 Combined
Workmans Comp
Dept of AG
Poison Control
Source 2004 Pesticide Incident Reporting and
Tracking (PIRT) Annual Report
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Washington State Pesticide Events - 2003
Source 2004 Pesticide Incident Reporting and
Tracking (PIRT) Annual Report
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Agricultural vs. Non-Agricultural Cases of
Poisonings
Source 2004 Pesticide Incident Reporting and
Tracking (PIRT) Annual Report
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Occupational versus Non-Occupational Cases of
Pesticide Poisoning
Source 2004 Pesticide Incident Reporting and
Tracking (PIRT) Annual Report
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Proportion of Poisonings
Ranked 8th Cause of Poisonings 102,754 cases in
2005 (4.2)
Adults
Children
Source Watson WA. 2004 Annual Report of the
American Association of Poison Control Centers
Toxic Exposure Surveillance System
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US Intentional vs. Accidental
Accidental
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Suicide
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6 suicide attempts used pesticides out of 196,164
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WHO Sentinel Surveillance
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Pesticide
cide to kill
Disinfectants
Fumigants
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Pesticide Chemical Families-grouping based on
similarities-

1. Similar chemically (similar structure)
2. Attacks pests in a similar way (toxicity)
3. Common treatment antidote

Pyrethroid PY
Organophosphate OP
Carbamate C
Organochlorine OC
Chlorophenoxy
Paraquat Diquat
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Pesticide Sample Label

• Type of pesticide (used for?)
• Company name
• Brand name
• Common/generic name (active ingredient)
• Chemical family (? atropine under 1st aid)
• Signal word (hazard level)

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Pesticide Classification Table
Type Company Name Brand Name Common Name Chemical Family Signal Class
1. Insecticide Gowen Supracide methidathion OP (Organophosphate) Danger-Poison Ib




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Exercise Classifying Pesticides
Pesticide Labels
COMPANY BRAND COMMON TYPE FAMILY SIGNAL Who
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
Bayer
Temik
Aldicarb
Insecticide
Carbamate
Danger-poison
la
Verdicon
Sevin
Carbaryl
Insecticide
Carbamate
Caution
ll
UCP Alliance
Thiodan
Endosulfan
Insecticide
Organochlorine
Warning
ll
Bayer
Guthion
Azinophos methyl
Insecticide
Organophospate
Danger-poison
lb
Dow
Dursban
Chlorpyrifos
Insecticide
Warning
ll
Organophospate
Syngenta
Gramoxone
Paraquat
Herbicide
Paraquat
Danger-poison
ll
Helena
Weed Rhap
2, 4-D
Herbicide
Chlorophenoxy
Danger-poison
ll
DuPont
Asana
Esfenverlate
Insecticide
Pyrethroid
Warning
lV
Bayer
Captan
Captan
Fungicide
Danger-poison
II
Max
Roundup
Glyphosate
Herbicide
Caution
U-IV
Fungicide
Mancozeb
Dow
Dithane
Caution
U-IV
Cerexagri-Nisso
III
Ziram
Fungicide
Ziram
Danger
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How toxic is it?
Source Richards, Kerry Penn State University
Extension Service
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Source Richards, Kerry Penn State University
Extension Service
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LD50
Lethal dose Amount of chemical it takes to kill
50 of an experimental population
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Source Richards, Kerry Penn State University
Extension Service
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DANGER/POISON extremely toxic by ingestion
DANGER extremely toxic high potential for skin
and eye irritation
Adapted from Richards, Kerry Penn State
University Extension Service
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Source Richards, Kerry Penn State University
Extension Service
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Insecticides

• ChE Inhibitors
• Organophosphates
• n-methyl carbamates
• Pyrethroids
• Pyrethrins (ocloresin extract of chrysanthemum)
• Pyrethroids (the synthetic derivative)
• Organochlorines (e.g. DDT)
• DEET
• Boric Acid
• Fluorides
• Nicotine
• Arsenicals

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Herbicides

• Chlorophenoxy herbicides (e.g. 2-4D)
• Paraquat and diquat
• Pentachlorophenol and dinitrocresol (wood
  preservatives)
• Copper chromium arsenate ( decks, fences, and
  childrens wood playground sets d/c 2003)

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Fungicides

• Hexachlorobenzene
• Thiram
• Maneb
• Methylmercury compounds

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Fumigants

• Cyanide,
• 1, 3-dichloropropane
• Metam sodium
• Methyl bromide
• Naphthalene
• Phosphine gas (from aluminum phosphide)

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Rodenticides

• Warfarin-related compounds
• Warfarin
• Coumarins
• Brodifacoum
• Difenacoum (so-called super warfarins)
• Others
• Thallium
• Zinc phosphide
• Sodium fluoroacetate

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Disinfectants

• Agents used for sanitization and sterilization in
  the home and hospital
• Registered as pesticides by the U.S. EPA
• Examples include
• Alcohols
• Chlorhexidine
• Hypochlorites
• Iodines
• Phenols
• Pine oil

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Organophosphates 30-240 Carbamates 15-30
General central nervous system Fatigue Dizziness Headache Tremors Ataxia Convulsions (uncommon w/carbamate) LOC (uncommon w/carbamate) Coma (uncommon w/carbamate)
From muscle over stimulation Muscle weakness Muscle cramps Muscle fasciculations
From gland over stimulation Salivary gland- excessive salivation Sweat gland- excessive sweating Lachrymal gland-excessive eye tearing
From organ over-stimulation Eyes Gastrointestinal Pulmonary Blurred vision (constricted pupils) Stomach cramps Nausea Vomiting Diarrhea Chest tightness Wheezing Cough Runny nose
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Pyrethroids
Pyrethroids are irritants to the eyes, skin and
respiratory tract. The symptoms last from 1-2
hours. Systemic toxicity from inhalation or
dermal absorption is low.
Normal use Paresthesias (cyno pyrethroids) Shortness of breath (wheezing) Mucous membrane irritation (throat nose) Skin itching
If ingested Loss of consciousness/coma Seizures (cyno-pyrethroids)
High doses Vomiting Diarrhea Excessive saliva Muscle fasciculation Ataxia Irritability to sound touch
Cyno-pyrethroids fenverlate, flucythrinate,
fluvalinate cypermethrine, deltapermethrin,
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Organochlorines 10 - 480lipophylic

• The nerves stimulating glands are not affected so
  you will NOT see
• excessive salivation
• excessive sweating
• excessive eye tearing
• (or over-stimulation of small muscles like)
• twitching eyelids

• CNS Effects
• Muscle Weakness
• Dizziness
• Headache
• Numbness
• Nausea/vomiting
• LOC
• Seizures
• Tremors
• Ataxia
• Anxiety/restlessness
• Confusion

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Paraquat
Paraquat is very toxic to the skin and mucous
membranes. Particles are too large to get deep
into the lungs, but once in the blood it
collects in the lungs. If ingested high case
fatality rate.
Skin dryness, cracks erythema blistering ulcerations
Nails discoloration splitting nails loss of nails
Respiratory tract cough nosebleeds sore throat
Eyes conjunctivitis ulceration, scarring, blindness
Ingestion lung fibrosis (stiff lungs) multi-system organ failure, specifically respiratory failure kidney failure
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DEETDIETHYLTOLUAMIDE

• Few toxic cases - given the widespread use
• Toxic if ingested
• Children toxic encephalopathy w/ heavy use on
  large surface area on kids ( ETOH - isopropyl or
  ethyl)
• Dermal problems tingling, irritation,
  desquamination, contact dermatitis, exacerbate
  pre-existing skin dz
• Kids use 5-6.5 formulations

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Boric AcidAnts, Cockroaches in Residences
broiled lobster appearance
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Boric Acid
Respiratory tract irritant Moderate skin
irritant
Historic antibacterial poisonings from burn
compresses, diaper powder, irrigation solutions

• Targets GI tract, skin, vasculature, brain
• Chronic ingestion more toxic than acute (13? ½
  life)
• Absorption via gut and abraded skin

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Fluorides

• Transformed in stomach to corrosive
  hydrofluoric acid ? thirst, nausea-vomiting,
  diarrhea, abdominal pain
• Fluoride ion reduces extra-cellular fluid
  concentrations of Ca and Mg ? hypocalcemic
  tetany
• Cardiac arrythmias- shock ? 2ndary to
  fluid/electrolyte imbalances, hypokalemia and the
  fluoride itself
• CNS ? H.A. muscle weakness, stupor, seizures and
  coma

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Focus on OPs

• Children at risk for neurodevelopmental problems
• Most commonly used insecticide in agriculture
• Common cause of poisoning

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Normal Electrical Nerve Impulse Transmission
Once acetylcholine is broken, it can no longer
transmit electrical nerve impulses. Electrical
nerve impulses stop and the muscles and glands
are quiet
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Organophosphate-Carbamate Disruption of
Electrical Nerve Impulse Transmission Therapeutic
Effect of Atropine
If an organophosphate (Op) or carbamate is
present, they bind with cholinesterase. This is
an irreversible effect with an Op but not with a
carbamate The bound cholinesterase cannot
penetrate acetylcholine to break it up. The body
continues to produce acetylcholine
unimpeded. This results in a build up of
acetylcholine with continuous electrical nerve
impulse transmission and over stimulation of
muscle and glands.
Atropine relieves the over stimulation of the
muscles and glands by reducing the amounts of
acetylcholine. The effect only lasts 15 minutes.
Therefore the dose must be repeated until the
organophosphate binding effect has worn off.
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Signs and Symptoms in Adults
Exercise Body Mapping
Miosis Blurring
Heart
Eye
CNS
Lungs
Glands
Muscle
GI

• Fatigue
• Dizziness
• Headache
• Tremors
• Ataxia
• Seizures
• LOC
• Coma
• Insomnia
• Mental ?

Tightness Wheezing Cough Rhinorrhea
Weakness Cramps Fasciculations
Tachy Brady ? BP ? BP
Abd. cramps Nausea Vomiting Diarrhea
Drooling Sweating Tearing
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Signs of Pesticide Poisoning in Children
Seizures
Lethargic sleepy
Coma
Can be confused with the flu